Pressure-retaining valve for air-brakes.



No. 697,694." Patented Apr. I5, 1902.

\ J. A. TOAL.

PRESSURE RETAINING VALVE FORAIR BRAKES.

(Application filed Nov. 29, 1901.

y '1 'LLLIIIIHI IIHIIIIllIHIIl l|lIIFIHIllllllHtllHllLllilHlllllHll (No Mqdel.)

lTED STATES PATENT- OFFICE.

JOHN A. TOAL, OF CLANCY, MONTANA, ASSIGNOR OF ONE-HALF TO PETER LEARY, OF OLANCY, MONTANA.

PRESSURE-RETAINING VALVE FOR AIR-BRAKES.

SPECIFICATION forming part of Letters Patent No. 697,694, dated April 15, 1902. Application filed November 29, 1901. Serial No. 83,995. (No 'model.) i

To aZZ whom it may concern: main casing; 19, a handle for turning the Be it known that I, JOHN A. TOAL,acitizen plug; 20, stops on the casing; 21, lugs upon of the United States, residing at Clancy, in the handle to engage the stops on the casing; the county of Jefierson and State of Montana, 22, a longitudinal groove in the plug extendhave invented new and useful Improvements ing a portion of the length of said plug only;

in Pressure-Retaining Valves forAir-Brakes, 23, a diametrical passage through the plug; of which the following is a specification. 24, a passage at right angles to the diamet- My invention relates to pressure-retaining rical passage; 25, passages from the plug to valves for air-brakes; and the object in view the low and high pressure retaining-valves;

to is the provision of means for retaining lim- 26, the full-release port in the casing which ited pressurewithin the brake-cylinders when is in communication with the groove in the the engineer recharges the auxiliary reserplug when the handle is in a vertical position, voirs, said pressure corresponding to the and 27 is a passage from the pipe 6 to the plug. weights of the individual cars comprising the As is well known to persons familiar with 15 train. the art, the brakes are applied by the en- The accompanying drawings illustrate one gineer exhausting air from the train-pipe to example of the physical embodiment of my the atmosphere, and when applied the passage invention constructed according to the best from the train-pipe to the auxiliary reservoir mode I have so far devised for the practical is closed, the passage from the auxiliary res- 20 application of the principle. ervoir to the brake opened, and the exhaust Figure 1 showsacar with myimprovements passage from the cylinder to the atmosphere applied to the fluid-pressure brake system closed. In recharging the reservoir the pass- Which is attached thereto. Fig. 2 is a secsage from the brake-cylinder to the atoms tional view of a duplex retaining-valve with phere is opened and the passage from the 25 the handle in position of full release. Fig. 3 train-pipe to the reservoir opened. shows the handle in the position it occupies W'hena train is descending a grade, it is when a relatively low pressure is retained in desirable to recharge the reservoir and retain the brake-cylinder. Fig. 1 shows the posithe brakes set with a pressure in each braketion of the handle when a relativelyhigh prescylinder corresponding to the weight of the 36 sure is retained in the brake-cylinder. car or car-load. My valve enables that result Referring to the several figures, the nnto be secured. At the top of a grade the moral 1 designates a car-body of any type; 2, brakesman turns the handles upon the empty the air-brake cylinder; 3, the auxiliary resor lightly-laden cars to the position shown in ervoir; i, the triple valve; 5, the exhaust- Fig. 3, so that the air to escape must lift the 35 port of the triple valve, and 6 the pipe leadvalve 12 and overcome the pressure of the ing from the triple-valve exhaust-port to a polight spring. Upon the heavily-laden cars sition near the top and end of the car, where the handle is turned to the position shown in it is readily accessible to the brakeman. Fig. 4, which opens the passage to the valve The numeral 7 designates the duplex valve let with the relatively stiff spring. When the b as a whole; 8, the casing of the valve; 9, the engineer recharges the auxiliary reservoir, perforated lugs by which the casing is secured pressure is retained within the several braketo the car; 10, two small cylindrical castings cylinders of the light and heavy cars correin connection with the main casting; 11, exsponding to the force exerted by the springs haust-ports in the castings; 12, the low-pres- 13 15 to seat the valves. The springs deter- 45 sure retaining-valve; 13, the low-pressure-remine the pressure retained, which may vary 5 taining-valve spring; 14, the high-pressure from ten, fifteen, or twenty pounds for the retaining-valve; 15, the high-pressure retainlighter cars up to approximately full or coming-valve spring; 16, removable caps at the pletely full pressure for the heavier cars. ends of the valve-castings; 17, the spring-ad- Upon reaching the level track or the bottom 50 j usting plugs; 18, a rotary plug located in the of the grade the handles are turned to the po- I00 -'sition,s hown in dotted lines, Fig. 2,so that the passage from the exhaust-port 5 of the triple valve is entirely open to the atmosphere by y'vay of the groove 22 in the plug and the port 26 in the casing. (Clearly shown in said u The 'di iiict tlt'ies and dangers attending the operation and control of trains upon steep and mountainous grades, whatever he the relative arrangement of the cars, are wellknown to practical railroad men and need not be herein'recited. The use of my inven-. tion Will wholly eliminate such difficulties and dangers, as itprovides means for retaining such pressure within the brake-cylinders as will control the individual car according to its weight or Weight and load.

It is obviousthat in practice modifications in construction may be introduced and equivalents used'for parts of the valve. For instance, I may substitute weighted valves for v the valves and springs shown, and the parts valves which can retain different pressures within the air-brake cylinder; and means for controlling the passage from the pipe to said valves.

2. The combination with an air-brake system, of a pipe connected to the exhaust-port of the triple valve; a duplex valve embracing two valves requiring different pressures to operate the same; and a plug'adapted to place the 'pipe in communication with the said valves alternately.

3.- The combination with an air-brake system, of a pipe connected to the exhaust-port of the triple valve; a duplex valve embracing a plurality of valves of unequal power; a plug adapted to place the pipe successively in communication with the valves; and means for opening a passage from the pipe to the atmosphere.

4. The combination with an air-brake sys tem, of a pipe connected to the exhaust-port of the triple valve; a duplex valve embracing a'plurality of valves held to their seats with unequal pressure; aplug with passages adapted to open communication between the pipe and'thevalves; and means in connectionwith the plug for opening a passage to the atmosphere.

In testimony whereof I affix my signature in presence of two witnesses- JOHN A. TOAL. I

Witnesses:

PETER LEARY, OAsIMIR KAMBER. 

